New York City Ballet has bestowed a rare honor on a member of its corps, commissioning two works from Justin Peck, the company said on Wednesday. One of the works, set to the music of Philip Glass, is to have its first performance at the Saratoga Performing Arts Center this summer. The second will have its premiere in the fall, during the company’s regular season, at Lincoln Center. The work will be an expanded version of “Tales of a Chinese Zodiac,” which Mr. Peck, 24, first presented in 2010 at the New York Choreographic Institute. It was set to songs by Sufjan Stevens, who will provide a new orchestration, the company said.